Lithium/graphite fluoride primary battery and method for its manufacturing

Abstract

A lithium/graphite fluoride primary battery prepared by a process which includes providing a graphite fluoride powder, mechanically milling the graphite fluoride powder so as to obtain an active material, providing a mixture comprising the active material and an electrically conductive carbon so as to form a part of a positive electrode, providing a body comprising lithium as a part of a negative electrode, and forming an electrochemical cell with the positive electrode and the negative electrode.

What is claimed is: 
     
       1. A lithium/graphite fluoride primary battery prepared by a process comprising:
 providing a graphite fluoride powder; 
 mechanically milling the graphite fluoride powder so as to obtain an active material; 
 providing a mixture comprising the active material and an electrically conductive carbon so as to form a part of a positive electrode; 
 providing a body comprising lithium as a part of a negative electrode; and 
 forming an electrochemical cell with the positive electrode and the negative electrode, 
 wherein, the active material has a BET surface area of from 250 to 300 m 2  g −1 . 
 
     
     
       2. The battery as recited in  claim 1 , wherein the graphite fluoride powder comprises a CFx compound where 0.1 ≦x ≦2. 
     
     
       3. The battery as recited in  claim 1 , wherein the electrically conductive carbon comprises a CFx compound where 1.0 ≦x ≦1.2. 
     
     
       4. The battery as recited in  claim 1 , wherein the mechanical milling of the graphite fluoride powder comprises a ball milling where the graphite fluoride powder is rotated in a ball mill at a frequency of from 100 to 400 rpm. 
     
     
       5. The battery as recited in  claim 4 , wherein the ball milling is preformed over a period of from 30 minutes to 6 hours. 
     
     
       6. The battery as recited in  claim 4 , wherein the ball milling is performed with a ball to powder ratio of from 5:1 to 100:1. 
     
     
       7. The battery as recited in  claim 1 , wherein the active material has a total pore volume of from 0.12 cm 3  g −1  to 0.15 cm 3  g −1 . 
     
     
       8. The battery as recited in  claim 1 , wherein the active material has a grain size of from 50 to 1000 nm. 
     
     
       9. The battery as recited in  claim 1 , wherein the positive electrode is provided by a process comprising:
 preparing a mixture comprising the active material, the electrically conductive carbon, and an organic solvent; 
 preparing a slurry of the mixture and spreading the slurry on an electrically conducting substrate; and 
 drying the slurry. 
 
     
     
       10. The battery as recited in  claim 1 , wherein the negative electrode is a lithium foil. 
     
     
       11. The battery as recited in  claim 1 , further comprising a separator. 
     
     
       12. The battery as recited in  claim 11 , wherein the separator is a glass fiber sheet. 
     
     
       13. The battery as recited in  claim 1 , further comprising an electrolyte. 
     
     
       14. The battery as recited in  claim 13 , wherein the electrolyte is a solution comprising at least one of an inorganic salt, ethylene carbonate (EC), and dimethyl carbonate (DMC). 
     
     
       15. A method for manufacturing a lithium/graphite fluoride primary battery, the method comprising:
 providing a graphite fluoride powder; 
 mechanically milling the graphite fluoride powder so as to obtain an active material; 
 providing a mixture comprising the active material and an electrically conductive carbon so as to form a part of a positive electrode; 
 providing a body comprising lithium as a part of a negative electrode; and 
 forming an electrochemical cell with the positive electrode and the negative electrode, 
 wherein, the active material has a BET surface area of from 250 to 300 m 2  g −1 . 
 
     
     
       16. The method as recited in  claim 15 , wherein the mechanical milling of the graphite fluoride powder comprises a ball milling where the graphite fluoride powder is rotated in a ball mill at a frequency of from 100 rpm to 400 rpm, for a period of from 30 minutes to 6 hours, and with a ball to powder ratio of from 10:1 to 50:1.